UN Climate Change chief Christiana Figueres says the NSW fires prove the world is "already paying the price of carbon".

AFP: Karim Jaafar

The United Nations says the New South Wales bushfires are an example of "the doom and gloom" the world may be facing without vigorous action on climate change.

The executive secretary of the UN Framework Convention on Climate Change, Christiana Figueres, says the fires prove the world is "already paying the price of carbon".

"The World Meteorological Organisation has not established the direct link between this wildfire and climate change yet, but what is absolutely clear is that the science is telling us there are increasing heatwaves in Asia, Europe and Australia," she told CNN.

"These [heatwaves] will continue. They will continue in their intensity and in their frequency."

Her comments come after deputy Greens leader Adam Bandt was accused of politicising the bushfires, when he claimed the Government's climate policies would lead to more fires in the future.

Key points

UN Climate chief Christiana Figueres says bushfires will be more frequent if no climate action is taken

She says the fires are evidence that 'we are already paying the price of carbon'

Greens MP Adam Bandt was accused of politicising the fires after linking them to climate change

Other climate scientists have backed Mr Bandt's position

Ms Figueres has criticised the Coalition's plan to repeal the carbon price

"It's October and we're having a tragic bushfire," he said last week.

"Meanwhile, Tony Abbott and his ministers have been... saying that they're going to take Australia backwards when it comes to combating global warming."

"But that's not the only scenario. We could, as humankind, we could take vigorous action and we could have a very different scenario"

Direct Action 'could be much more expensive'

Ms Figueres also criticised the Federal Government's so-called Direct Action policy on climate change, saying it may prove more expensive than a carbon price.

"What the new Government in Australia has not done is it has not stepped away from its international commitment on climate change, so what they're struggling with now is not what are they going to do but how are they going to get there," she said.